At present,intensity modulated radiation therapy has been the main treatment of nasopharyngeal carcinoma.In the course of 6-7 weeks,most physicians use the initial formulation of the radiotherapy plan.Studies have indicated that the reduction of primary tumor and lymph nodes,as well as the reduction of normal tissue and body surface profile due to the weight loss,will affect the dose distribution of the target and the organs at risk,so as to influence the therapeutic effect of some patients.Therefore,it is necessary to reset and modify the target volumes during the radiotherapy for nasopharyngeal carcinoma.

Objective To quantify the setup error ( SE ) in breast cancer patients treated with intensity modulated radiotherapy (IMRT) based on cone beam CT (CBCT), and to explore the feasibility of using several CBCT scans to presume and correct SE in the treatment for breast cancer patients.Methods Eighteen breast cancer patients after breast conserving surgery who underwent whole breast IMRT were included in this study.Three dimensional interfraction motion before and after on-line CBCT-based corrections were quantified.The on-line CBCT-based corrections were performed using automated greyscale match.The system SE (Σ) and random error (σ) were calculated for each patient based on the consecutive multiple online scanning based on CBCT (≥5) .The trends in magnitudes of Σand σwere assessed during the treatment. Results The magnitude variation ofΣwas less than 1 mm before and after on-line CBCT-based corrections. As the CBCT scanning times increase ( before 10 times ) , the Σin anteroposterior ( AP ) direction was increased significantly, and σin three dimensional directions was also increased after 7 times of CBCT scanning.After on-line CBCT-based corrections, theΣshowed a steady trend by variation near zero for the first 20 times irradiation;but after 20 times, theΣin AP and superoinferior ( SI) directions was increased slightly (less than 0.5 mm), and σdecreased in three-dimensional directions.There were no significant differences forΣ,σand setup margin ( SM) before and after on-line CBCT-based corrections in all three directions ( P>0.05) .Conclusions For breast cancer patients who underwent IMRT after breast conserving surgery, the setup error is relatively stable during the whole irradiation.The first 5 CBCT scans are suitable to presume and correct SE, and also can be used as the right time for adaptive radiotherapy planning revision.

Objective To quantify the setup error ( SE ) in breast cancer patients treated with intensity modulated radiotherapy (IMRT) based on cone beam CT (CBCT), and to explore the feasibility of using several CBCT scans to presume and correct SE in the treatment for breast cancer patients.Methods Eighteen breast cancer patients after breast conserving surgery who underwent whole breast IMRT were included in this study.Three dimensional interfraction motion before and after on-line CBCT-based corrections were quantified.The on-line CBCT-based corrections were performed using automated greyscale match.The system SE (Σ) and random error (σ) were calculated for each patient based on the consecutive multiple online scanning based on CBCT (≥5) .The trends in magnitudes of Σand σwere assessed during the treatment. Results The magnitude variation ofΣwas less than 1 mm before and after on-line CBCT-based corrections. As the CBCT scanning times increase ( before 10 times ) , the Σin anteroposterior ( AP ) direction was increased significantly, and σin three dimensional directions was also increased after 7 times of CBCT scanning.After on-line CBCT-based corrections, theΣshowed a steady trend by variation near zero for the first 20 times irradiation;but after 20 times, theΣin AP and superoinferior ( SI) directions was increased slightly (less than 0.5 mm), and σdecreased in three-dimensional directions.There were no significant differences forΣ,σand setup margin ( SM) before and after on-line CBCT-based corrections in all three directions ( P>0.05) .Conclusions For breast cancer patients who underwent IMRT after breast conserving surgery, the setup error is relatively stable during the whole irradiation.The first 5 CBCT scans are suitable to presume and correct SE, and also can be used as the right time for adaptive radiotherapy planning revision.

Intensity modulated radiation therapy(IMRT)has become the mainstay of treatment modal-ity for nasopharyngeal carcinoma(NPC). The whole treatment course generally continues 7 to 8 weeks. With the radiotherapy proceeding,the patients exhibit oropharyngeal reaction aggravating,weight losing and tumor shrinking,resulting in the changes of tumor target and surrounding tissue. Those changes may influence the dose distribution of tumor and organ at risk. It is necessary to modulate target volume during radiotherapy of NPC.

Objective This study was designed to compare the safety and efficacy of fast track surgery (FTS) with conventional perioperative management in colonl cancer patients undergoing radical resection.Methods From May 2011 to May 2013,66 patients with colorectal cancer were randomly assigned to FTS group and control group.Outcomes were assessed by length of postoperative hospital stay,medical cost,nutritional status,gut function,and postoperative complication.Results FTS group was associated with a significantly shorter postoperative hospital stay,lessmedical cost,earlier first passage of flatus,less loss of body weight in the postoperative period compared with control group,and there were no differences in morbidity or mortality between two groups.Conclusion The radical resection under the guidence of fast track rehabilitation is safe and effective method.Significantly reduce patients' perioparative stess response and accelerate the recovery.

Objective To analyze artifacts of gross tumor volume (GTV) and correlated factors in each phase images of four dimensional CT (4DCT) for peripheral lung cancer based on three dimensional CT (3DCT) assisted with active breathing control.Methods Nineteen patients with peripheral lung cancer underwent 3DCT (CTFB) and 4DCT simulation scans during free breathing and then underwent 3DCT simulation scans in end inspiration hold (CTEIH) and end expiration hold (CTEEH) assisted with active breathing control.The relative deviations (Devref) between the reference GTV (GTVref) and the GTVsdelineated based on CTFB (GTVFB) and all phases of 4DCT were calculated respectively.Correlations between GTVref and Devmax and between the tumor motion in the cranio-caudal (CC) direction and Devref were analyzed.Results The maximum median Devref of GTV was GTVFB with 17.83％,and the maximum median Devref of the GTV in all phases of 4DCT was GTV30 with 17.20％.A significant negative correlation was found between GTVEIH and Devmax (r =-0.691,P =0.001).The Devref was crrnelated with the tumor motion amplitude in the CC direction (r =0.323-0.617,P =0.005-0.150).The partial regression coefficient of influence of GTVref size and motion amplitude in the CC direction to the tumor Devmax were -0.500 and 0.583,P =0.002 and 0.001,respectively.Conclusions The GTV artifacts in different phase of 4DCT for the peripheral lung cancer were different to each other,and the influence of target displacement to artifacts was larger than that of target volume,so artifacts could be reduced by controlling breathing to reduce target displacement.

Objective To compare the position,volume and matching index (MI) of patientspecific internal gross tumor volume (IGTV)delineated by 4 different approaches based on three- dimensional and four - dimensional CT ( 3 DCT and 4 DCT ) image for primary esophageal cancers.Methods Thirteen patients with primary esophageal cancer underwent 3DCT and 4DCT simulation scans during free breathing,and the patient were divided into group A (tumor located in the proximal thoracic esophagus) and B (tumor located in the mid-and distal thoracic esophagus).IGTV were delineated using four approaches: The gross tumor volume (GTV) contours from 10 respiratory phases were combined into IGTV10 ;IGTV2 was acquired by combining the GTV from 0％ and 50％ phases; IGTVMIP was the GTV contour delineated from the maximum intensity projection (MIP) ;IGTV3D was acquired from the enlargement of 3 DCT-based GTV by each spatial direction on the motion amplitude measured in the 4DCT.ResultsTarget movement in lateral (LR),anterio-posterior (AP),superio-inferior (SI) directions showed no statistically significant difference (0.11 cm,0.09 cm,0.18 cm,respectively; χ2 =1.06,P=0.589),and there was no statistically significant difference in centroid positions between IGTV10 and IGTV2 or IGTV3D in group A (t =-2.24,-0.00,P =0.089,- 1.000 ),MI between IGTV10 and IGTV2,IGTV10 and IGTV3D were 0.88,0.54,respectively. For group B, target movement amplitude in SI direction was bigger than in LR, AP ( 0.47 cm,0. 15cm,0. 12 cm,X2= 12.00,P = 0.002).Therewasno significantdifference betweenIGTV10 andIGTV3D inLR, AP, SI ( t =- 0.80.- 0.82,- 1.16,P = 0.450.0.438.0.285 ), MI was 0.59 ; but the target center coordinates was demonstrated significant difference in SI between IGTV10 and ICTV2 for group B ( t = 2.97.P = 0.021 ), Mlwas 0.86.Thevolume of IGTVMIPwassmaller thanIGTV10 ( t =- 2.84,P = 0.025 ), but the position of IGTv10 and ICTVMIp were with no statistically significant difference in the LR,AP,SI ( t =- 0.25,0. 84. - 1.22,P = 0. 809,0.429.0.263 ) ,MIbetweenIGTV10andIGTVMIp was 0.78.Conclusions Patient-specific IGTV can be acquired from 4DCT with correct target coverage while avoiding a geographic miss for the thoracic esophageal cancer,but IGTV2 and IGTVMIP can not contain all the information about primary tumor position,shape.and size at different phases of the respiratory cycle.

ObjectiveTo investigate the effect of the displacement of the selected silver clip in the different respiratory state achieved by active breathing control ( ABC ) system on the displacement of the geometry constituted by all of the silver clips at the border of the cavity in external-beam partial breast irradiation (EB-PBI).MethodsTwo sets of CT images in state of moderate deep inspiratory breathing hold (mDIBH),deep expiratory breathing hold (DEBH),and free breath (FB) were acquired in the same CT simulation assisted by ABC system for each of the 27 patients after breast conservative surgery.All silver clips in the cavity were delineated based on each set of CT images.Thereafter,the irregular geometry based on the silver clips as the vertices was automatically formed.Four selected clips located at the top,bottom,lateral border and medial border of the cavity were correspondingly manually registered based on automatic registration of the CT images acquired in the same or different state of respiration including mDIBH,FB,and DEBH.The displacement of center of the geometry in the direction of right-left (RL),anterior-posterior (AP),and superior-inferior (SI) separately based on automatic registration and manual registration was evaluated.The difference of the displacement was analyzed by Kruskal-Wallis H-test and Kolmogorov-Smirnov Z-test.Results When registered between mDIBH and mDIBH,FB and FB,DEBH and DEBH,the differences of the displacement of the center of geometry were not statistically significant (H =0.00 - 1.76,P=0.184-0.954). When registered between mDIBH and DEBH,the differences were statistically significant ( Z =11.31 - 23.00,P =0.000 - 0.001 ).There were statistically significant differences in the displacement of geometry center based on the selected silver clip between different registration forms in AP and SI directions (Z=4.76-25.54,P=0.000-0.029).ConclusionsThe difference of intrafraction displacement of the geometry constituted by the clips between the same respiratory states in the three dimensional direction is not statistically significant,but the difference is statistically significant between the different respiratory states in AP and SI directions.

ObjectiveTo explore the feasibility,efficacy and cosmetic effect of three-dimensional conformal external beam partial breast irradiation (EB-PBI) after breast-conserving surgery for the selected Chinese early stage breast cancer patients.MethodsFrom June 2003 to December 2010,Forty-four early stage breast cancer patients underwent EB-PBI after breast-conserving surgery.Twenty patients had CT simulation scan in moderate deep inspiration breathing hold,and twenty-four patients in free breathing.EB-PBI was planned and delivered by three-dimensional conformal radiotherapy (3DCRT)with four noncoplanar beams.The prescribed dose was 3.40 Gy per fraction in thirty-nine patients and 3.85 Gy per fraction in five patients,twice per day at an interval of at least six hours,in five consecutive days.Results The number of patients with follow up time of 2,3 and 5 years were 39,31 and 16.Grade 1 acute radiationinduced dermatitis was observed in 17 patients (39％) at three months.Cosmesis was good or excellent in all cases at six months after radiotherapy and in 95％ cases at two years after radiotherapy.The 2-,3-and 5-year local control rates were 100％,99％ and 94％,respectively.The 2-,3-,and 5-year survival rates were all 100％ and no metastases occurred.Conclusions EB-PBI delivered by 3DCRT is feasible for selected Chinese early stage breast cancer patients after breast-conserving surgery.The cosmetic effect,local control rate and long-term survival rate are satisfactory,and acute radiation toxicity is very low.

OBJECTIVE: To measure the intra-fraction displacements of the mediastinal metastatic lymph nodes by using four-dimensional CT (4D-CT) in non-small cell lung cancer (NSCLC). MATERIALS AND METHODS: Twenty-four patients with NSCLC, who were to be treated by using three dimensional conformal radiation therapy (3D-CRT), underwent a 4D-CT simulation during free breathing. The mediastinal metastatic lymph nodes were delineated on the CT images of 10 phases of the breath cycle. The lymph nodes were grouped as the upper, middle and lower mediastinal groups depending on the mediastinal regions. The displacements of the center of the lymph node in the left-right (LR), anterior-posterior (AP), and superior-inferior (SI) directions were measured. RESULTS: The mean displacements of the center of the mediastinal lymph node in the LR, AP, and SI directions were 2.24 mm, 1.87 mm, and 3.28 mm, respectively. There were statistically significant differences between the displacements in the SI and LR, and the SI and AP directions (p < 0.05). For the middle and lower mediastinal lymph nodes, the displacement difference between the AP and SI was statistically significant (p = 0.005; p = 0.015), while there was no significant difference between the LR and AP directions (p < 0.05). CONCLUSION: The metastatic mediastinal lymph node movements are different in the LR, AP, and SI directions in patients with NSCLC, particularly for the middle and lower mediastinal lymph nodes. The spatial non-uniform margins should be considered for the metastatic mediastinal lymph nodes in involved-field radiotherapy.
Adult ; Aged ; Aged, 80 and over ; Carcinoma, Non-Small-Cell Lung/*radiography/radiotherapy ; Contrast Media/diagnostic use ; Female ; Four-Dimensional Computed Tomography/*methods ; Humans ; Iohexol/analogs & derivatives/diagnostic use ; Lung Neoplasms/*radiography/radiotherapy ; Lymphatic Metastasis/*radiography ; Male ; Mediastinum/radiography ; Middle Aged ; Radiographic Image Interpretation, Computer-Assisted ; Statistics, Nonparametric